The present invention relates to a vehicle body and a vehicle with such a vehicle body.
A front region of a vehicle body typically has two longitudinal members, which extend in the longitudinal direction of the vehicle, and a bumper cross member, which is fastened to the ends of the longitudinal members of the vehicle. The bumper cross member extends more or less over the entire width of the vehicle or at least protrudes transversely beyond the longitudinal members. The longitudinal members usually extend inside the left and right wheel suspension or, more specifically, inside the left and right wheel wells and outside a drive unit. In the event of a frontal collision with minimal overlap, the vehicle impacts the obstacle outside of the respective longitudinal member.
Recently, there is a move towards improving the energy absorptivity of a vehicle body during a frontal collision with small overlap. WO 2009/072450 A1 provides additional body frame elements that extend in the longitudinal direction and are arranged outside the longitudinal members. These body frame elements extend from a bumper cross member over a wheel well up to an A pillar of the body. As a result, the energy is absorbed, in particular during impact with small overlap, not only by the conventional longitudinal member, but is also introduced by the bumper cross member over the wheel well as far as into the A pillar.
An object of the present invention is to provide a vehicle body that makes it possible to improve the introduction of energy into a longitudinal member in the case of a frontal collision with small overlap.
This and other objects are achieved by a vehicle body comprising a longitudinal member and a bumper cross member. The vehicle body has a cantilever support member that extends transversely to the longitudinal member along a transverse axis of the vehicle and that is fastened in a torque resistant manner to the longitudinal member. In this case, the cantilever support member is arranged such that it protrudes into an intermediate space between a wheel mount and the bumper cross member. To do so, the bumper cross member projects beyond the longitudinal member in the transverse direction of the vehicle body.
Consequently, a cantilever support member within the context of the invention is a support member that is fixed on one side. The cantilever support member projects from the longitudinal member in the direction of the outside or exterior of the vehicle. The bumper cross member is preferably fastened to a front end of the longitudinal member.
The arrangement according to the invention provides that in the event of a frontal collision of the vehicle body with small overlap, not only the bumper cross member, but also the cantilever support member can absorb energy and can deflect this energy into the longitudinal member due to its being fastened to the longitudinal member.
If there exists a defined distance between the bumper cross member and the cantilever support member, then first the bumper cross member is deformed until it strikes against the cantilever support member; and then, secondly, this cantilever support member supports, as required, the bumper cross member and deflects the energy into the longitudinal member.
A frontal collision with small overlap within the context of the present invention is a frontal collision of the vehicle body with an obstacle, where the obstacle is located in essence laterally outward relative to a longitudinal axis of the longitudinal member, i.e. on a side of the longitudinal member, on which a wheel mount may be found.
The expression “in essence transversely to the longitudinal member” means that the cantilever support member can also extend at an angle deviating from the transverse axis of the vehicle, but it is more or less directed along the transverse axis of the vehicle.
The bumper cross member may be a rear or a front bumper cross member of the vehicle body. The wheel mount may be a left or a right wheel mount. Furthermore, the longitudinal member may be a left or right longitudinal member.
The present invention provides that in the event of a frontal collision with small overlap, the cantilever support member may serve to absorb energy and to introduce this energy into the longitudinal member. A frontal collision with small overlap may be defined as an overlap of the vehicle body of about 25% or less in the direction of travel of the vehicle.
According to a further development of the present invention, the cantilever support member is a body element that is produced separately from the longitudinal member. In particular, the cantilever support member can be connected to the longitudinal member as a separate body element by way of a welded joint, a riveted joint and/or a threaded joint.
This feature allows the present invention to be applied to existing vehicle bodies or, more specifically, to the vehicle bodies known from the prior art. In this case only the additional cantilever support member is fastened to the existing longitudinal member.
Furthermore, the present invention provides that a switchable structural element can be arranged between a free end of the cantilever support member and a bumper cross member. The free end of the cantilever support member is the end of the cantilever support member that is not fastened to the longitudinal member. Hence, it is the end of the cantilever support member that is not clamped. A switchable structural element is a structural element of the vehicle body that exhibits varying, selectable properties independently of a specific boundary condition, such as the strength of the impact.
Especially in the case of the vehicle body according to the invention, the switchable structural element may be constructed in such a way that in the case of an impact at a speed that is greater than or equal to a threshold speed, the switchable structural element is essentially rigid, and that in the case of an impact at a speed that is less than the threshold speed, the switchable structural element is movable. The expression “essentially rigid” in this context means that the switchable structural element is not movable, but may well include a deformability at high load levels.
Consequently, in the event of a frontal collision below the threshold speed, only the bumper cross member is initially stressed, so that no energy can be introduced into the longitudinal member by way of the cantilever support member. In the case of a speed that is greater than or equal to the threshold speed, the energy is transferred directly from the bumper cross member to the free end of the cantilever support member and, thus, to the longitudinal member.
According to an additional further development of the present vehicle body, a support element can be arranged on a side of the longitudinal member that is located opposite the cantilever support member in such a way that the longitudinal member is laterally supported when the cantilever support member is subjected to stress due to a frontal collision.
Especially in the event of the above described frontal collision with small overlap, the energy is introduced, as explained, into the longitudinal member by way of the cantilever support member. In particular, a torque that can cause a lateral bending or buckling of the longitudinal member is applied to the connection between the cantilever support member and the longitudinal member. The support element can counteract this lateral deformation or lateral buckling of the longitudinal member by laterally supporting the longitudinal member on the other side, i.e. the inner side of the vehicle. The support element can support, for example, the longitudinal member on a drive unit, such as an engine block. As a result, the energy absorptivity of the longitudinal member as a whole is increased, and the drive unit also absorbs the collision energy.
According to a further development of the present invention, the vehicle body can include a tension element that connects a free end of the cantilever support member to a bumper cross member in the region of the longitudinal member.
A tension element in the context of the invention means that it involves a structural element that can be subjected in essence only to tension and on compression cannot absorb any significant amount of energy. One end of the tension element is connected to the free end of the cantilever support member. The other end of the tension element is connected to the bumper cross member in the region of the longitudinal member. Thus, the tension element extends obliquely from the free end of the cantilever support member in the direction of the longitudinal member to the front. “In the region of the longitudinal member” means that the tension element is fastened to the bumper cross member in a region, where the bumper cross member is attached to the longitudinal member.
If in the case of a frontal collision with small overlap the cantilever support member is subjected to stress, then the tension element, which is attached to the bumper cross member, is subjected to tension and allows the cantilever support member and/or the longitudinal member to absorb more energy. As a result, the tension element enables an improvement in the energy absorption in the event of a frontal collision with small overlap. According to a preferred further development of the invention, the vehicle body has a left and a right longitudinal member as well as a left and a right cantilever support member.
The left cantilever support member projects from the left longitudinal member in the transverse direction of the vehicle to the left, whereas the right cantilever support member projects from the right longitudinal member in the transverse direction of the vehicle to the right.
This feature allows the vehicle body to exhibit an improved energy absorptivity both in the event of a frontal collision with small overlap on the left side, i.e. a left frontal collision, as well as also in the event of a frontal collision with small overlap on the right side, i.e. a right frontal collision.
According to a preferred further development of the present invention, in particular of the vehicle body with a left and a right longitudinal member and a left and a right cantilever support member, the free end of the right cantilever support member is connected to a free end of the left cantilever support member by way of a tension element. Furthermore, the tension element of this further development extends around the front ends of the right and left longitudinal member.
Thus, in the course of a frontal collision with small overlap the tension element is subjected to stress in such a way that it pulls at the free end of the right cantilever support member. Hence, in the event of a left frontal collision the right cantilever support member and, thus, also the right longitudinal member act as an additional support and can also absorb energy when the left cantilever support member is subjected to stress. Such an approach can increase even more the energy absorptivity of the vehicle body during a frontal collision with small overlap.
According to a further development of the vehicle body, wherein the tension element connects the free ends of the left and the right cantilever support member to each other, the tension element extends around the entire bumper cross member. Therefore, in the event of a frontal collision with small overlap, the deformation of the bumper cross member also acts on the tension element in the form of subjecting the tension element to stress, so that the energy absorption of the vehicle body is further improved. As described above, this feature also allows energy to be dissipated over the right longitudinal member in the case of a left frontal collision.
According to a further development of the vehicle body of the present invention, the front end of the right cantilever support member is connected to a front end of a right support strut of a right wheel well by way of a right tension element of the wheel well. Furthermore, the front end of the left cantilever support member is connected to a front end of a left support strut of a left wheel well by way of a left tension element of the wheel well.
Thus, in the event of a right frontal collision, the left tension element of the wheel well is subjected to stress, so that the left cantilever support member as well as the left support strut of the left wheel well can absorb energy. Conversely, the right wheel well tension element is subjected to stress during a left frontal collision, so that the right cantilever support member and the right support strut of the right wheel well can absorb energy.
The above described tension elements, including the tension elements of the wheel well, may be cables or bands. The bands can be formed from a woven fabric.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.